/**
 * 冒泡排序
 */
Array.prototype.bubbleSort = function() {
  for (let i = 0; i < this.length - 1; i++) {
    for (let j = 0; j < this.length - 1 - i; j++) {
      if (this[j] > this[j + 1]) {
        let aux = this[j];
        this[j] = this[j + 1];
        this[j + 1] = aux;
      }
    }
  }
  return this;
};

console.log([5, 4, 3, 2, 1].bubbleSort().toString()); // 1,2,3,4,5
